1. Field of the Invention
This invention relates to an ink ribbon to be used for producing a dry transfer material and, more particularly, relates to an ink ribbon which can produce a dry transfer image on a transfer sheet that may be subsequently transferred to a receiving material.
2. Description of Related Art
Recently, a device for producing dry transfer material which comprises a transfer sheet for dry transfer material and a ribbon cartridge in which an ink ribbon for producing the dry transfer material is stored has been developed and used widely. As such a device, Tape Printer "P-touch" manufactured by Brother industries, Ltd. is well known. A thermal head is installed in the device for producing the dry transfer material. The ink ribbon is brought in contact with a transfer sheet by the thermal head and a number of heating elements, aligned on the thermal head, are caused to generate heat according to electrical signals whereby the ink on the ribbon in contact with the heating elements is heated through a base sheet of the ribbon and fused onto the transfer sheet.
Further, as described in U.S. Pat. No. 4,870,427 (corresponding to Japanese Laid-Open Patent Publication No. 63-128990 and Japanese Laid-Open Patent Publication No. 63-128991), the ink ribbon for producing dry transfer material comprises an ink layer which is arranged on a film-like ribbon substrate and contains a resin having pressure-sensitive adhesive property and a coloring matter therein, and a control layer which is arranged on the ink layer and contains a resin having a thermo-sensitive adhesive property.
Another ink ribbon for producing dry transfer material comprises, as described in Japanese Laid-Open Patent Publication No. 63-251287, a layer arranged on a film-like ribbon substrate that contains a resin having pressure-sensitive adhesive property and an ink layer pressure-sensitive adhesive property and an ink layer which is arranged on the layer and contains a resin having thermal-sensitive adhesive property, with a coloring matter therein.
The user installs a ribbon cartridge, in which an ink ribbon for producing dry transfer material is stored, in the device for producing the dry transfer material. The user then inputs the characters or figures, by means of a key board or other external data source, the user wants recorded on the dry transfer material. Following the data input, the heat-generating elements of the device corresponding to characters or figures to be recorded are heated according to the input character and figure data. The ink from the ink ribbon for producing the dry transfer material is transferred to a transfer sheet formed by a transparent resin sheet, whereby the dry transfer material, that is the transferred image consisting of characters and figures formed on the transfer sheet, is produced. To use the dry transfer material, the user presses the dry transfer material against a desired surface and transfers the ink image to the surface with the application of pressure to a side opposite the ink image.
However, with current transfer materials, there is a problem that the quality of the transferred image is not good as produced by transferring from the dry transfer material to the receiving surface.
To transfer the known dry transfer material, the user must place the side of the transfer sheet having the ink transfer image in contact with the surface of the receiving material, such as paper, plastic, metal, or wood, and then the user must rub, for a long period of time, the back side of the transfer sheet.
However, it was difficult to obtain a high quality transferred image because collapse and spreading of the ink transferred image results if the transfer sheet is insufficiently fixed with respect to the receiving material surface and the transfer sheet shifts position during the rubbing and transfer.
The inventors of the present invention studied the problem and found the reason why the user had to keep rubbing the transfer sheet for such a long period of time was because the pressure-sensitive adhesive property of the resin, such as described in EXAMPLE 2 of column 18 of U.S. Pat. No. 4,870,427, was weak.